Unfortunately, it's unlikely that you will improve by 150 points in 2 weeks. I have never personally heard of someone achieving this (and I've been working with the GMAT for more than 15 years).
I know you don't want to hear that, but I want you to know so that you can make some hard decisions for yourself. If you take the test in 15 days, your score is likely to be around the level that it is now - perhaps a bit higher, but probably not 150 points higher.
You said that the deadline for your program is the end of April. Most programs allow you to take the test right up until the deadline, so why can't you take the test at the end of April? Do they have a test deadline of end of March?
Next, you've made good improvement so far. I know you want more - but I just want to acknowledge that you've done some hard work already and you've picked up about 90 points. That's great.
How's your timing? Almost everyone struggles with timing on this test and, in particular, I find that people whose scores are stagnating tend to struggle especially hard with timing.
Read this:http://www.manhattangmat.com/blog/index ... to-win-it/
and this:http://www.manhattangmat.com/blog/index ... anagement/
In terms of specific feedback on what to study and how, I need to know more about your strengths and weaknesses. Use the below article to help you analyze your MGMAT CATs:http://www.manhattangmat.com/blog/index ... ice-tests/
Then come back here and share your analysis. Note: do not just post the raw data. We want to see your analysis - what you think it means and what you think you should do. You actually need to develop this skill so that you can figure out your next steps for yourself over time, so make this your first step. We'll tell you whether we agree with your analysis and also advise you about what to do. :)